Symphony.

Is it vital, for performance or other, to be certain that one have figured the database structure out before starting to use a site built with S2? Or won't it matter if fields are added or removed later down the road?

Well, for starters, I believe that at least certain fields cannot have their "type" changed after the fact. In other words, if something needs to be a section link, you'll need to know that beforehand. Not sure exactly how this breaks down, though (i.e. if it's all fields that can't be changed or just some). No idea about how adding/removing fields later affects the DB.

That's correct (as I understand it). You can't change a field's type once it's created. So if you have data in your fields and want to change its data type, you'd need to delete the field from the section (thereby removing the data too) and re-add it as another type.

However you can add and remove fields from a section as often as you like, so your sections can grow if your site or requirements grow. But just remember that deleting a field will also delete all data for that field, in all entries in that section.

I wasn't thinking about changing field types, but adding and removing fields. Thanks for the input.